Attachment for locomotive air-brakes.



No. 739,907. PATENTED SEPT.29, 1903 H. R. NEVENS.

ATTACHMENT FOR LOGOMOTIVE AIR BRAKES. APPLIOATION FILED P212. 10, 1902.

N0 MODEL.

UNITED STATES.

Y Patented September 29, 1903.

PATENT OFFICE.

HERBERT annvnns, or PORTLAND, MA'INE.

SPECIFICATION forming part of Letters Patent No. 739,907, dated September 29, 1903.

. Application filed February 10, l902- Serial No. 98,287. (No model.)

To all whom, it may concern.-

Be it known that I, HERBERT R. NEVENS, a citizen of the United States of America, and a resident of Portland, Cumberland county, State of Maine, have inventedfcertain new and useful Improvements in: Attachments for Locomotive Air-Brakes, of which the following is a specification.

My invention relates to an attachment to the air-brakes of railroad-trains whereby the same may be set bya brakeman on the track in front of the train.

It sometimes happens that when a brakeman is sent back on the track to flag an oncoming train his signals are not seen on account of fog or darkness or the carelessness of the engineer and a rear-end collision results. The object of the present device is to prevent such collisions by so constructing the air-brake apparatus that the brakeman may automatically apply the brakes if his signals are not seen. -I accomplish this object by providing a valve for releasing the pressure on the train line-pipe, with a depending arm for operating said valve in front of the front truck of the locomotive and with its lower end adjacent to the top of the rail, in connection with a tripping-plate adapted to be carried by the brakeman and fastened on top of the rail, so that as the arm comes in contact" with the tripping-plate the valve is opened and the brakes set.

I illustrate my invention by means of the accompanying drawings; in which Figure 1 is a side elevation of my attachment, showing the forward truck, partly in section. Fig. 2 is an enlarged side elevation with the valve in section. elevation. Fig. 4 is a plan view of the tripping device, and Fig. 5 is a modification of the arm.

A represents the wheel of the forward truck. a is the axle, and c is the frame. Secured to the frame is the piston-valve B, connecting bya pipe n with the train line-pipe m. A cam is provided by which the piston-valve may be opened to relieve the pressure on the train line-pipe. As here shown, a cam f is secured to a transverse shaft 6 and acts against the valve-stem z' of the piston-valve. In the end of the piston are two ports 19 and p, the port 19 communicating with the open air and the Fig. 3 is a front port 19 with the whistle 0, which is preferably located in the cab of the engine. Secured to the valve-stem and against the end of the cylinder is the piston t,-haviug an opening i through it out of line with the ports, so that when the piston is shut the ports are closed. 'A guide it is located back of the piston to guide the valve-stem.

V The working edge of the cam f has a concaveportion fi against which the end of the valve-stem rests normally, so that when the cam is turned in either direction the valvestem is pressed inward and the valve opened. On each side of the concave portion f there is a convex portion f, here shown as concentric with the center of the cam and far enough away to hold the valve open when the stem reaches this part of the cam. Thus when the cam is turned in either direction the valve is first 'forced open by the surface f and held open by thesurfa'ce f. The cam is turned to open the valve by means of a depending arm d,one of which hangs down from each end of the shaft directly over the rail and in front of the wheel A. The shaft e is jourualed in the boxes q, secured to the frame by the braces g.

The lower end of the arm at is adjacent to the track and easily thrown back by any obstruction' on the track. For the purpose of swinging the arm to open the valve the brakeman is provided with a tripping-plate adapted to be attached to the track. As here shown,

' I show an elongated plate J, having clips j,

by which it is fastened to the track, and having a crowning portion j, which rises above the surface of the rail and against which the lower end of the arm is adapted to hit. For the purpose of extra precaution a topedo k may be secured to the tripping-plate.

The operation of the device is as follows: When the brakeman desires to stop the oncoming train, he flags the train in theusual manner, and if he gets the signal from the engineer that his flag is seen he does not make use of the tripping-plate; but if he does not get the signal he secures the trippingplate to the rail, and when the locomotive comes along the front wheels run into the end of the tripping-plate and hold it firmly down, while the arm (1 comes along and striking against the crowning portion j turns the Ice shaft and the cam and opens the valve, causing the pressure on the train line-pipe to be relieved, and so setting the brakes.

It will be seen that the tripping device will seldom have to be used; butit is taken along by the brakeman when he starts back with his flag or lantern as an extra precaution to be used if his signals are not seen.

In Fig. 5 I show a modified form of arm having a Wheel 5, which tends to lift as it strikes the tripping-plate instead of being thrown back, as does the arm of Fig. 1.

I claim- 1. In a device for automatically setting airbrakes on a railroad-train, the combination of a piston-valve for relieving the pressure on the train line-pipe, a valve-stem for said valve, a cam acting against said valve-stem to open the valve against the pressure, ashaft for said cam, a depending arm on said shaft and a tripping device on the track adapted to strike said arm.

of a piston-valve secured to the truck for relieving pressure on the train-pipe, a cam acting against the valve-stem of said valve, a transverse shaft for said cam jonrnaled in said truck, an arm depending from each end of said shaft having its lower end adjacent to the top of the rail.

3. In a device for automatically setting airbrakes on railroad-trains, the combination of a piston-valve secured to the truck for relieving pressure on the train-pipe, a cam acting against the valve-stem of said valve, said cam having a portion concave with respect to said valve-stein for opening the valve and a convex portion for holding the valve open, a transverse shaft for said cam, an arm depending from each end of said shaft having its lower end adjacent to the top of the rail.

Signed at Portland, Maine, this 3d day of February, 1902.

HERBERT R. NEVENS.

Witnesses:

CHAS. B. BERRY, S W. BATE. 

